Method of Dyeing Polyester

ABSTRACT

The present invention relates to a method of dyeing polyester-containing textile material characterised in that the textile material is treated with a liquor containing (a) at least one disperse dye and (b) at least one compound of the formula (1), wherein G 1  and G 2 , independently of one another, are C 1 -C 4 alkyl or together are pentamethylene, Z 1  and Z 2  are methyl, Or Z 1  and Z 2  together form a bridging member which is unsubstituted or substituted by an ester, ether, hydroxyl, oxo, cyanohydrin, amido, amino, carboxyl or urethane radical, and E is oxyl or hydroxyl.

The present invention relates to a method of dyeing polyester-containing textile material.

Reduction sensitivity of azo disperse dyes is a problem in the polyester dyeing process. The extent of dye destruction in the dye liquor depends on the chemical structure of the dye, the processing conditions and the type of dyeing auxiliaries. This reduction sensitivity seriously affects the reproducibility of the shade, especially in combination dyeings. Critical dyeing conditions are fully flooded bulk dyeing machines, wherein the air and the oxygen are completely removed. Lignin sulfonate dispersing agents are widely used because of their low price and their reliability, especially at high dyeing temperatures (130-135° C.), but due to their reduction power these dispersants tend to destroy reduction-sensitive disperse dyes in the dye liquor.

It has now surprisingly been found that the reductive decomposition of sensitive disperse dyes under bulk dyeing conditions can be substantially reduced when small amounts of oxides or hydroxides of sterically hindered amines are added to the dyeing liquor.

The present invention relates to a method of dyeing polyester-containing textile material characterised in that the textile material is treated with a liquor containing

(a) at least one disperse dye and (b) at least one compound of the formula

-   -   wherein     -   G₁ and G₂, independently of one another, are C₁-C₄alkyl or         together are pentamethylene,     -   Z₁ and Z₂ are methyl, or Z₁ and Z₂ together form a bridging         member which is unsubstituted or substituted by an ester ether,         hydroxyl, oxo, cyanohydrin, amido, amino, carboxyl or urethane         radical, and     -   E is oxyl or hydroxyl.

In principle, any disperse dye known for dyeing polyester can be used in the process according to the invention.

Preferably, component (a) is a compound of formula

-   wherein R₁ denotes C₁-C₄alkyl, -   R₂ is hydrogen, bromo, chloro, cyano or nitro, -   R₃ is bromo, chloro, cyano or nitro, -   R₄ is hydrogen, methyl or methoxy, -   R₅ and R₆, independently of one another, are ethyl, benzyl,     2-cyanoethyl, 2-hydroxyethyl, 2-methoxyethyl, 2-ethoxyethyl,     2-(2-methoxyethoxy)-ethyl, 2-(2-ethoxyethoxy)-ethyl,     2-acetyloxyethyl, methoxycarbonylmethyl, ethoxycarbonylmethyl,     1-methoxycarbonylethyl or 1-ethoxycarbonylethyl, -   R₇ is hydrogen, bromo, chloro, cyano or nitro, -   R₈ is bromo, chloro, cyano or nitro, -   R₉ is methyl or ethyl and -   R₁₀ is hydrogen, methyl, methoxy, acetylamino or propionylamino.

The disperse dyes of formulae (2), (3) and (4) are known or can be prepared according to known methods.

The following disperse dyes are preferFred: C.I. Disperse Yellow 114, C.I. Disperse Yellow 211, C.I. Disperse Yellow 54, C.I. Disperse Orange 25, C.I. Disperse Orange 30, C.I. Disperse Orange 31, C.I. Disperse Orange 44, C.I. Disperse Orange 61, C.I. Disperse Red 50, C.I. Disperse Red 73, C.I. Disperse Red 82, C.I. Disperse Red 167, Disperse Red 167:1, C.I. Disperse Red 324, C.I. Disperse Red 356, C.I. Disperse Red 376, C.I. Disperse Red 382, C.I. Disperse Red 383, C.I. Disperse Violet 93:1, C.I. Disperse Violet 107, C.I. Disperse Blue 56, C.I. Disperse Blue 60, C.I. Disperse Blue 79:1, C.I. Disperse Blue 93:1, C.I. Disperse Blue 165, C.I. Disperse Blue 165:1, C.I. Disperse Blue 183, C.I. Disperse Blue 284, C.I. Disperse Blue 291, C.I. Disperse Blue 337, C.I. Disperse Blue 354 and C.I. Disperse Blue 378.

Particularly preferred as component (a) are the compounds of formula

The compounds of formula (1) likewise are known and are described, for example, in WO 01/85857.

The component (b) to be used in the method according to the invention also includes the ammonium salts obtainable by reaction of the compound of formula (1) with acids.

Preference is given to the components (b) of the formula

-   wherein E is oxyl or hydroxyl, -   R₁₁ is hydrogen or methyl and -   n=1 or 2,     -   if n=1,         -   Y is hydrogen, C₁-C₁₈alkyl, C₂-C₁₀alkenyl, propargyl,             glycidyl or C₂-C₅₀alkyl which is unsubstituted or             substituted by 1-10 hydroxyl groups and which may be             interrupted by 1-20 oxygen atoms, or         -   Y is C₁-C₄alkyl substituted by —COOR₁₂, in which R₁₂ is             hydrogen, C₁-C₄alkyl or phenyl, if n=2,         -   Y is C₁-C₁₂alkylene, C₄-C₁₂alkenylene, xylylene or             C₁-C₅₀alkylene, which is unsubstituted or substituted by             1-10 hydroxyl groups and which may be interrupted by 1-20             oxygen atoms. -   Suitable compounds of the formula (Ia) are, for example, -   bis(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)sebacate, -   bis(1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl)sebacate, -   1-hydroxy-2,2,6,6-tetramethyl-4-acetoxypiperidinium citrate, -   1-oxyl-2,2,6,6-tetramethyl-4-acetamidopiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium bisulfate, -   1-oxyl-2,2,6,6-tetramethyl-4-oxopiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-oxopiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-oxopiperidinium acetate, -   1-oxyl-2,2,6,6-tetramethyl-4-methoxypiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-methoxypiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-methoxypiperidinium acetate, -   1-oxyl-2,2,6,6-tetramethyl-4-acetoxypiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-acetoxypiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-acetoxypiperidinium acetate, -   1-oxyl-2,2,6,6-tetramethyl-4-propoxypiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-propoxypiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-propoxypiperidinium acetate, -   1-hydroxy-2,2,6,6-tetramethyl-4-(2-hydroxy-oxapentoxy)piperidinium     acetate, -   1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidine, -   1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium chloride, -   1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium acetate, -   1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium bisulfate, -   1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium citrate and -   bis(1-hydroxy-2,2,6,6-tetramethylpiperidin-4-hydroxypiperidinium)citrate.

Preferably, the textile material is treated with a liquor containing as component (b) 1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine of the formula

In the process according to the invention the dyes according to component (a) can be applied individually or in mixtures.

Advantageously, mixtures of two or three dyes (di- or tri-chromicity) may be used. Mixtures of four or more dyes, however, can also be used, especially in the production of combination shades.

The amounts in which the individual dyes are used in the dye liquors can vary within wide limits depending on the desired depth of shade. In general, amounts of from 0.01 to 35% by weight, especially from 0.1 to 15% by weight, based on the fibre material to be dyed have proved to be advantageous.

The liquor ratio can be selected from within a wide range, for example within a range of from 1:2 to 1:50, preferably from 1:3 to 1:15.

The liquor can comprise, in addition to components (a) and (b) as defined above, further customary additives, such as dispersing, levelling and wetting agents, penetration accelerants, pH-regulators and antifoams.

Suitable dispersing agents can be nonionic or anionic. Nonionic dispersing agents are, for example, reaction products of alkylene oxides, like ethylene oxide or propylene oxide, with fatty alcohols, fatty amines, fatty acids, phenols, alkylphenols and carboxamides.

Anionic dispersing agents are, for example, lignin sulfonates and salts thereof, alkyl- or alkylaryl-sulfonates, alkylaryl polyglycol ether sulfates, alkali metal salts of the condensation products of naphthalenesulfonic acids and formaldehyde, polyvinyl sulfonates and ethoxylated novolaks.

In a preferred embodiment, the textile material is treated with a liquor additionally containing a lignin sulfonate as dispersing agent.

The textile material can be used in any form, e.g. in the form of fibres, yarn, woven fabric, knitted fabric or non-woven.

Polyester-containing textile material in terms of the invention includes pure polyester as well as blends containing polyester and further synthetic, semi-synthetic or natural textile material, like polyester/cotton, polyester/wool or polyester/elastan blends.

Preferably, the textile material is polyester or a polyester/cotton blend.

Typically, polyester fibre materials are dyed from an aqueous dispersion by the exhaust process in the presence of customary anionic or nonionic dispersants and in the presence or absence of customary swelling agents (carriers) at pH 3.5-5.5, in particular at pH 4.0-5.0, in the temperature range from 80 to 150° C., preferably from 90 to 140° C.

Special apparatus is not required. For example, customary dyeing apparatus, e.g. open baths, winch becks, jigs, or paddle, jet or circulation apparatus, may be used.

In order to enhance the wet-fastness properties of dyed synthetic polyester fibres, an aftertreatment can be carried out at a pH value of e.g. from 7 to 12, especially from 7 to 9, and a temperature of e.g. from 30 to 100° C., especially from 50 to 80° C., to remove any unfixed dye. In the case of intense hues, especially on fibre blends, unfixed dye can advantageously be removed reductively, by adding to the alkaline aftertreatment bath a reducing agent, for example a hydrosulfite, e.g. sodium hydrosulfite. Dye that has been fixed in the fibre material is not attacked by the treatment. Advantageously, the amount of reducing agent added is e.g. from 0.1 to 8.0% by weight, especially from 0.5 to 5.0% by weight, based on the weight of the aftertreatment bath.

Following the method according to the invention there are obtained dyeings on polyester fibre material, which exhibit a substantial improvement in terms of the depth of shade, without the fastness-to-washing or fastness-to-light properties being adversely affected.

The Examples that follow serve to illustrate the invention. The temperatures are given in degrees Celsius, parts are parts by weight, and percentages refer to percentages by weight, unless otherwise specified. Parts by weight relate to parts by volume in the same ratio as kilograms to litres.

EXAMPLE 1

10 g knitted 100% polyester fabric is dyed in an autoclave by preparing a dye liquor of 100 ml total volume containing 45 mg of a commercial formulation of C.I. Disperse Blue 165:1, 50 mg of a compound of formula (101), 200 mg of a commercial dispersing agent (REAX 85A, lignin sulfonate, supplied by BASF), 50 mg of a commercial wetting and defoaming agent (ALBAFLOW® UNI, supplied by Huntsman), 100 mg ammonium sulfate and about 0.1 ml of acetic acid 80% to get pH of 4.5. The fabric is put into the dye liquor and just before closing the autoclave it is thoroughly washed with nitrogen to simulate a fully flooded bulk dyeing machine, where all the air and the oxygen with it is removed completely. The liquor is heated up with 2° C. per minute to 135° C. and is kept at 135° C. for 60 minutes. After a warm and cold rinse the dyeing is treated in a reductive clearing: 20 min/70° C. in a liquor containing 5 ml/I caustic soda 36° Be, 2 g/l sodium hydrosulfite conc. and 1 g/l of a commercial nonionic washing agent (ERIOPON® OL, supplied by Huntsman). The dyeing is rinsed, neutralized and dried.

The depth of shade is determined by reflectance measurement and expressed in percentage in relation to the depth of shade which is obtained by a benchmark process carried out with same fabric, dye and auxiliaries but using UNIVADINE® DP (dispersing agent, supplied by Huntsman) instead of the compound of formula (101), which is set as 100%.

COMPARATIVE EXAMPLE 2

The dyeing process described in Example 1 is repeated under omission of the compound of formula (101).

Example 1 and Comparative Example 2 are repeated with other dyes. The resulting depth of shade values are summarized in Table 1.

TABLE 1 Series with 100% polyester fabric Comparative Example 2 Example 1 45 mg C.I. Disperse Blue 165:1 30% 71% 51 mg C.I. Disperse Blue 79.1 73% 98% 70 mg C.I. Disperse Blue 378 76% 93%

The same series of benchmark process, Inventive Example 1 and Comparative Example 2 is made with a fabric blend of 65% grey cotton and 35% polyester instead of the 100% polyester fabric and without the 200 mg of commercial lignin sulfonate dispersing agent (REAX 85A) in the comparative example 1 and in the inventive example 2.

The resulting depth of shade values are summarized in Table 2.

TABLE 2 Series with fabric blend of 65% cotton/ Comparative Inventive 35%polyester without REAX 85A Example 2 Example 1 45 mg C.I. Disperse Blue 165:1 45% 62% 51 mg C.I. Disperse Blue 79:1 68% 87% 70 mg C.I. Disperse Blue 378 73% 85%

The same series of benchmark process, Comparative Example 2 and Example 1 is made with a fabric blend of 65% cotton and 35% polyester instead of the 100% polyester fabric and without the 200 mg of commercial lignin sulfonate dispersing agent (REAX 85A) and without the washing with nitrogen. The resulting depth of shade values are summarized in Table 3.

TABLE 3 Series with fabric blend of 65% cotton/ 35% polyester without REAX 85A and Comparative Inventive without nitrogen washing Example 2 Example 1 45 mg Disperse Blue 165:1 81% 92% 51 mg Disperse Blue 79:1 85% 92% 70 mg Disperse Blue 378 90% 92%

EXAMPLE 3

5 g knitted 100% polyester fabric is dyed in an autoclave with a dye liquor of 50 ml total volume containing 75 mg of a commercial formulation of C.I. Disperse Red 277 (Solvent Red 197), 20 mg of a compound of formula (101), 100 mg of a commercial wetting and defoaming agent (ALBAFLOW® UNI, supplied by Huntsman), 50 mg ammonium sulfate and about 0.05 ml of acetic acid 80% to get pH of 4.5. The liquor is heated up with 2° C. per minute to 135° C. and is kept at 135° C. for 60 minutes. After a warm and cold rinse the dyeing is subjected to a reductive aftertreatment: 20 min/70° C. in a liquor containing 5 ml/I caustic soda 36° Be, 2 g/l sodium hydrosulfite conc. and 1 g/l of a commercial nonionic washing agent (ERIOPON® OL, supplied by Huntsman). The dyeing is rinsed, neutralized and dried.

COMPARATIVE EXAMPLE 4

The dyeing process described in Example 3 is repeated under omission of the compound of formula (101).

Result: The dyeing of the Inventive Example 3 provides a significantly more brilliant shade and a significantly stronger fluorescence compared to the dyeing of the Comparative Example 4.

EXAMPLE 5 AND COMPARATIVE EXAMPLE 6

Example 3 and 4 are repeated by replacing 75 mg Disperse Red 277 with 75 mg Disperse Red 362 (Solvent Red 196) providing the same positive effect on shade and fluorescence in the case of Example 5 (use of the compound of formula (101)) compared to Example 6. 

1. A method of dyeing polyester-containing textile material characterised in that the textile material is treated with a liquor containing (a) at least one disperse dye and (b) at least one compound of the formula

wherein G₁ and G₂, independently of one another, are C₁-C₄ alkyl or together are pentamethylene, Z₁ and Z₂ are methyl, or Z₁ and Z₂ together form a bridging member which is unsubstituted or substituted by an ester, ether, hydroxyl, oxo, cyanohydrin, amino, amino, carboxyl or urethane radical, and E is oxyl or hydroxyl.
 2. A method according to claim 1, wherein the textile material is treated with a liquor containing as component (a) a compound of formula

wherein R₁ denotes C₁-C₄ alkyl, R₂ is hydrogen, bromo, chloro, cyano or nitro, R₃ is promo, chloro, cyano or nitro, R₄ is hydrogen, methyl or methoxy, R₅ and R₆, independently of one another, are ethyl, benzyl, 2-cyanoethyl, 2-hydroxyethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-(2-methoxyethoxy)-ethyl, 2-(2-ethoxyethoxy)-ethyl, 2-acetyloxyethyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, 1-methoxycarbonylethyl or 1-ethoxycarbonylethyl, R₇ is hydrogen, bromo, chloro, cyano or nitro, R₈ is bromo, chloro, cyano or nitro, R₉ is methyl or ethyl and R₁₀ is hydrogen, methyl, methoxy, acetylamino or propionylamino.
 3. A method according to claim 1, wherein the textile material is treated with a liquor containing as component (a) a compound of formula


4. A method according to claim 1, wherein the textile material is treated with a liquor containing as component (b) a compound of the formula

wherein E is oxyl or hydroxyl, R₁₁ is hydrogen or methyl and n=1 or 2, wherein if n=1 Y is hydrogen, C₁-C₁₈ alkyl, C₂-C₁₀ alkenyl, propargyl, glycidyl or C₂-C₅₀ alkyl which is unsubstituted or substituted by 1-10 hydroxyl groups and which may be interrupted by 1-20 oxygen atoms, or Y is C₁-C₄ alkyl substituted by —COOR₁₂, in which R₁₂ is hydrogen, C₁-C₄ alkyl or phenyl, and wherein if n=2, Y is C₁-C₁₂ alkylene, C₄-C₁₂ alkenylene, xylylene or C₁-C₅₀ alkylene, which is unsubstituted or substituted by 1-10 hydroxyl groups and which may be interrupted by 1-20 oxygen atoms.
 5. A method according to claim 1, wherein the textile material is treated with a liquor containing as component (b) 1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine of the formula


6. A method according to claim 1, wherein the textile material is treated with a liquor additionally containing a lignin sulfonate.
 7. A method according to claim 1, wherein the textile material is polyester or a polyester/cotton blend.
 8. A method according to claim 1, wherein the treatment with the dyeing liquor is followed by a reductive after-treatment.
 9. A method according to claim 8 wherein sodium hydrosulfite is used in the reductive after-treatment step. 